Too much moaning!
Well it’s another month down the road and the deadwood/keel is done – to be fair to Selway Fisher most of my troubles with this are entirely self inflicted, and by comparison to some other designs, Paul’s are much simpler and well thought out for the beginner (and in fact the first sentence of the instructions for the Golden Bay say that it’s not designed for the first time builder, so the fact I am almost ready to turn over the hull is a tribute to his design!).
Keel Bolts and Drilling
The deadwood is attached to the hull by 17 12mm stainless steel bolts (a little under 8 meters of studding in my case). This results in a very strong structure securing the hog to the deadwood. The only difficulty is that where the stern tube is inside the deadwood one needs to “short bolt” the deadwood with one length of bolt above the stern tube securing the upper lifts and one below the stern tube securing the lower lifts to the hull/hog.
By using the West System suggested approach of placing the half bolts into an oversized hole and then filling with liquid epoxy (having first greased the stud) one can create “cast-in nuts” of epoxy which secure the bolt into the timber. Given that these “nuts” can be about 8 to 10 inches in length they are quite strong enough to allow you to “dog-up” the nuts on the upper and lower ends of the studs without pulling the stud out of the wood.
In fact the major time consuming part is that one needs to bolt up each “lift” of timber while the epoxy attaching it to it’s adjacent mate sets. Then you have to extract the bolt while the next lift is fitted. I made this harder by arranging the scarfs in the wrong direction, so all the bolts had to come out to tuck each new timber under the scarf on the previous one.
Then, if you forget to grease one, you REALLY discover how strong the epoxy bond is – I actually managed to sheer one 12mm steel stud in half trying to get it out!
Measure once look twice!
The old adage is “measure twice, cut once”, but in my case the “look twice” thing is even more important. While fitting the final (upper) section of one of the keel bolts I was happily drilling down towards a line I had marked to indicate the position of the stern tube (to be sure I stopped drilling in time) when I suddenly had momentary heart failure realising that the line I was drilling towards was on the far side of the stern tube!!!! ARRGGG – but for once the gods were smiling on me. I stopped and discovered I had JUST noticed in time, and no harm was done – however I later discovered that the gods were grinning not smiling; as a few days later when re-tightening the stud into its epoxy nut for the final time, I managed to drive it through the end of the (over-long) hole and straight thru the stern tube!!! <air turns blue>….
So I effected a “patch” to the stern-tube by turning up and inserting a nylon plug into the stern tube to cover the hole I had drilled into it, and then pouring more epoxy down the stud hole to “seal the breach” and then (with some trepidation and liberal application of a large hammer) retrieve the nylon block – so I think I recovered the situation, but time will tell!
I tell you – this boat-building malarkey can be very stressful.
The outer stem on Befur is constructed from a number of 5mm iroko lamination attached to the planking/inner stem. I was hoping I could cold-bend these around a former, but it became clear as the second one shattered that this was not to be.
SO, with the aid of a borrowed steam wallpaper stripper and a length of 6″ soil pipe (which which turned into an over-scale approximation of limp spaghetti in the process) we managed to steam the lamination so that I could clamp them to a template of the stem and then epoxy them together …
Two lessons here 1) make sure the epoxy has REALLY cured before removing the clamps (or you get a quite spectacularly explosive delamination event) and 2) make sure that the template is strong enough to withstand the desire of the lamination to re-straighten (because you will discover when the epoxy HAS set that the resulting laminated structure will resist ALL of your attempts to persuade it back to the required shape).
Now this time the gods were smiling because the misshapen stem caused me to realise that the line I was planning for the bottom of the deadwood was wrong. What was needed was to ensure that the finished deadwood was “straight”, so that it would sit properly on the keel rollers on the trailer (which are in a straight line) – and that in fact the error on the stem laminations would allow that to happen… So a few more iroko jig-saw pieces and a deal more thickened epoxy and the whole thing was done. The pictures show the above processes. (The panorama makes the bottom of the deadwood look curved, but that is just a distortion in the picture.)
..and now to the painting….
So the last job before turning the hull over is to fill and prime the hull (top coats will come later) and fix a stainless steel rubbing strip to the keel/stem to withstand minor navigational errors!